Aquatic Resource Use by Indigenous Australians in Two Tropical River Catchments: the Fitzroy River and Daly River

Abstract

Indigenous people of northern Australia make extensive use of wild resources as a source of food, in their art and craft, and for medicinal purposes. These resources are part of a socially and culturally significant landscape. Using data collected from household surveys across two catchments in northern Australia, the Daly River, Northern Territory (NT) and the Fitzroy River, Western Australia (WA), we describe indigenous aquatic resource use patterns. The former is a perennial system with extensive vegetated wetlands that can remain inundated for 4-5 months, while the latter can cease to flow during the winter dry season (May-October) and its floods usually last for weeks. Subsistence strategies depend on seasonal availability of a wide array of aquatic species and are attuned to the life histories and movement patterns of key species, such as Long-necked Turtle (Chelodina rugosa) and Magpie Goose (Anseranas semipalmata). Indigenous households harvested resources from different habitats. Our results show a clear progression from use of the main river channel shortly after the wet season to use of billabongs late in the dry season in the Daly River, and a constant reliance on the main river channel and tributaries in the Fitzroy River. Difference in the main species utilised appears strongly related to habitat use, with four of the five most commonly harvested in the Daly catchment being non-fish species associated with billabong habitats. Commonly harvested species from the Fitzroy catchment included small bodied species used as bait and two popular food species, Black Bream (Hephaestus jenkinsi) and Catfish (Neoarius spp.). Results suggest that indigenous subsistence strategies are vulnerable to changes in the natural systems that provide the "ecosystem goods," particularly annual inundation of floodplains that drives productivity and provides habitat for some key species. Water resource developments, such as river regulation and increased abstraction for irrigated agriculture, could adversely affect a highly valued customary component of the indigenous economies of tropical Australia.